The invention relates to methods and tools for cleaving optical fibers.
Optical fibers are used increasingly frequently in waveguides and in communications systems, generally, wherein light energy is transmitted through very long distances within optical fibers with little or no concomitant energy losses. Devices using optical fibers often must be coupled, and such coupling requires the severance of and the reconnecting thereof of the transmitting fibers, which are made, generally, of glass. Loss of light energy at a coupling is detrimental to most transmissions and is to be avoided.
A junction between light fibers should be as near-perfect as possible; that is, the glass-to-glass interface should abut precisely one fiber to another, to minimize energy losses and signal imperfections at these junctures. To accomplish precise joining, a precision cleaving tool must be employed.
Miles of optical fibers are installed “in the field”, that is, removed from precision instrumentation. Various cleaving tools have been devised for field use, which provide various degrees of acceptability for the cleaved joint and for ease of operation, which also is of paramount importance in field use. Repeatability and consistency in cleavage are important considerations for any field tool.
It is well known that an optical fiber which is bent and then scribed or nicked will break at the scribe as a result of the variation in tensile stress across the cross-section of the fiber created by the bend. The break will generally be brittle and leave only slight imperfections across the fiber cross-section which can be removed by polishing, to produce an acceptable, virtually imperfection—free surface and subsequent joint.
An example of a known scribe-and-break tool for field use is found in U.S. Pat. No. 5,301,868. That patent discloses a scribe-and-break tool for fracturing the free end of an optical fiber said to be suitable for hand-holdable configurations and field use. The tool has an elongated body and a plunger that actuates a blade for scribing the free end of an optical fiber retained in tension within a depressible head that extends outwardly from the body. The free end of the optical fiber contacts the blade, thereby scribing the free end of the fiber causing the free end to break off.
See also the patents referred to and distinguished in U.S. Pat. No. 5,301,868; especially U.S. Pat. No. 5,063,672 which discloses an alternative hand held tool for scoring and severing an optical fiber and is said to be suitable for field use.